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Static Electricity
Static electricity is an imbalance of electric charges within or on the surface of a material. The charge remains until it can move away by an electric current or electrical discharge. The word "static" is used to differentiate it from electric current, current electricity, where an electric charge flows through an electrical conductor. A static electric charge can be created whenever two surfaces contact and/or slide against each other and then separate. The effects of static electricity are familiar to most people because they can feel, hear, and even see sparks if the excess charge is neutralized when brought close to an electrical conductor (for example, a path to ground), or a region with an excess charge of the opposite polarity (positive or negative). The familiar phenomenon of a static shockmore specifically, an electrostatic dischargeis caused by the neutralization of a charge. Causes Materials are made of atoms that are normally electrically neutral because they contai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static On The Playground (48616367)
Static may refer to: Places *Static Nunatak, in Antarctica *Static, Kentucky and Tennessee, U.S. *Static Peak, a mountain in Wyoming, U.S. **Static Peak Divide, a mountain pass near the peak Science and technology Physics *Static electricity, a net charge of an object **Triboelectric effect, due to frictional contact between different materials *Static spacetime, a spacetime having a global, non-vanishing, timelike Killing vector field which is irrotational *Statics, a branch of physics concerned with physical systems in equilibrium **Hydrostatics, the branch of fluid mechanics that studies fluids at rest Engineering *Static pressure, in aircraft instrumentation and fluid dynamics **Static port, a proprietary sensor used on aircraft to measure static pressure *White noise or static noise, a random signal with a flat power spectral density **Radio noise, in radio reception **Noise (video), the random black-and-white image produced by televisions attempting to display a weak or inco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humidifier
A humidifier is a household appliance or device designed to increase the moisture level in the air within a room or an enclosed space. It achieves this by emitting water droplets or steam into the surrounding air, thereby raising the humidity. In the home, point-of-use humidifiers are commonly used to humidify a single room, while whole-house or furnace humidifiers, which connect to a home's HVAC system, provide humidity to the entire house. Medical ventilators often include humidifiers for increased patient comfort. Large humidifiers are used in commercial, institutional, or industrial contexts, often as part of a larger HVAC system. Overview Humidification calculation : Humidity per hour: X = '' Air changes per hour (ACPH) * M³ * density of air * humidity ratio'' :: Humidity per day: X * 24 * The air changes per hour (ACPH) ranges wildly based on: ** Ventilation: Values may be obtained from the HVAC maintainer that routinely (typically every third year or so) tests the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrocardiography
Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity through repeated cardiac cycles. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the heart using electrodes placed on the skin. These electrodes detect the small electrical changes that are a consequence of cardiac muscle depolarization followed by repolarization during each cardiac cycle (heartbeat). Changes in the normal ECG pattern occur in numerous cardiac abnormalities, including: * Cardiac rhythmicity, Cardiac rhythm disturbances, such as atrial fibrillation and ventricular tachycardia; * Inadequate coronary artery blood flow, such as myocardial ischemia and myocardial infarction; * and electrolyte disturbances, such as hypokalemia. Traditionally, "ECG" usually means a 12-lead ECG taken while lying down as discussed below. However, other devices can record the electrical activity of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mains Voltage
Mains electricity, utility power, grid power, domestic power, wall power, household current, or, in some parts of Canada, hydro, is a general-purpose alternating-current (AC) electric power supply. It is the form of electrical power that is delivered to homes and businesses through the electrical grid in many parts of the world. People use this electricity to power everyday items (such as domestic appliances, televisions and lamps) by plugging them into a wall outlet. The voltage and frequency of electric power differs between regions. In much of the world, a voltage (nominally) of 230 volts and frequency of 50 Hz is used. In North America, the most common combination is 120 V and a frequency of 60 Hz. Other combinations exist, for example, 230 V at 60 Hz. Travellers' portable appliances may be inoperative or damaged by foreign electrical supplies. Non-interchangeable plugs and sockets in different regions provide some protection from accidental u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Shock
An electrical injury (electric injury) or electrical shock (electric shock) is damage sustained to the skin or internal organs on direct contact with an electric current. The injury depends on the Current density, density of the current, tissue resistance and duration of contact. Very small currents may be imperceptible or only produce a light tingling sensation. However, a shock caused by low and otherwise harmless current could startle an individual and cause injury due to jerking away or falling. A strong electric shock can often cause painful Spasm, muscle spasms severe enough to Joint dislocation, dislocate joints or even to Bone fracture, break bones. The loss of muscle control is the reason that a person may be unable to release themselves from the electrical source; if this happens at a height as on a Overhead power line, power line they can be thrown off. Larger currents can result in tissue damage and may trigger ventricular fibrillation or cardiac arrest. If death res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety Boots
A steel-toe boot (also known as a safety boot, steel-capped boot, steel toecaps or safety shoe) is a durable boot or shoe that has a protective reinforcement in the toe which protects the foot from falling objects or compression. Safety shoes are effective in keeping the feet of industrial workers safe from sharp and heavy objects while working in factories. Safety footwear now comes in many styles, including sneakers, clogs, and dress shoes. Some are quite formal, for supervising engineers who must visit sites where protective footwear is mandatory. Some brands of steel-toe footwear have become fashionable within subcultures such as skinhead, punk, and rivethead. While brands that were previously renowned within the fashion industry have also diversified into the safety footwear market, industrial brands like Caterpillar, Rock Fall and JCB have also issued licenses to produce safety footwear. Safety boot Safety boots are used by tradespeople to protect from environme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antistatic Strap
An antistatic device is any device that reduces, dampens, or otherwise inhibits electrostatic discharge, or ESD, which is the buildup or discharge of static electricity. ESD can damage electrical components such as computer hard drives, and even ignite flammable liquids and gases. Many methods exist for neutralizing static electricity, varying in use and effectiveness depending on the application. Antistatic agents are chemical compounds that can be added to an object, or the packaging of an object, to help deter the buildup or discharge of static electricity. For the neutralization of static charge in a larger area, such as a factory floor, semiconductor cleanroom or workshop, antistatic systems may utilize electron emission effects such as corona discharge or photoemission that introduce ions into the area that combine with and neutralize any electrically charged object. In many situations, sufficient ESD protection can be achieved with electrical grounding. Symbology Vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antistatic Bag
An antistatic bag is a bag used for storing electronic components, which are prone to damage caused by electrostatic discharge (ESD). These bags are usually plastic polyethylene terephthalate (PET) and have a distinctive color (silvery for metallised film, pink or black for polyethylene). The polyethylene variant may also take the form of foam or bubble wrap, either as sheets or bags. Multiple layers of protection are often used to protect from both mechanical damage and electrostatic damage. A protected device can be packaged inside a metalized PET film bag, inside a pink polyethylene bubble-wrap bag, which is finally packed inside a rigid black polyethylene box lined with pink poly foam. It is important that the bags only be opened at static-free workstations. Dissipative antistatic bags, as the name suggests, are made of standard polyethylene with a static dissipative coating or layer on the plastic. This prevents buildup of a static charge on the surface of the bag, as i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductor Device
A semiconductor device is an electronic component that relies on the electronic properties of a semiconductor material (primarily silicon, germanium, and gallium arsenide, as well as organic semiconductors) for its function. Its conductivity lies between conductors and insulators. Semiconductor devices have replaced vacuum tubes in most applications. They conduct electric current in the solid state, rather than as free electrons across a vacuum (typically liberated by thermionic emission) or as free electrons and ions through an ionized gas. Semiconductor devices are manufactured both as single discrete devices and as integrated circuit (IC) chips, which consist of two or more devices—which can number from the hundreds to the billions—manufactured and interconnected on a single semiconductor wafer (also called a substrate). Semiconductor materials are useful because their behavior can be easily manipulated by the deliberate addition of impurities, known as dopin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clothes Dryer
A clothes dryer (tumble dryer, drying machine, drying device, or simply dryer) is a powered Home appliance, household appliance that is used to remove moisture from a load of clothing, bedding and other textiles, usually after they are washed in the washing machine. Many dryers consist of a rotating drum called a "tumbler" through which heated air is circulated to evaporate moisture while the tumbler is rotated to maintain air space between the articles. Using such a machine may cause clothes to Shrinkage (fabric), shrink or become less soft (due to loss of short soft fibers). A simpler non-rotating machine called a "drying cabinet" may be used for delicate fabrics and other items not suitable for a tumble dryer. Other machines include steam to de-shrink clothes and avoid ironing. Tumble dryers Tumble dryers continuously draw in the Ambient air quality criteria, ambient air around them and heat it before passing it through the tumbler. The resulting hot, humid air is usually vent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washing Machine
A washing machine (laundry machine, clothes washer, washer, or simply wash) is a machine designed to laundry, launder clothing. The term is mostly applied to machines that use water. Other ways of doing laundry include dry cleaning (which uses alternative cleaning fluids and is performed by specialist businesses) and ultrasonic cleaning. Modern-day home appliances use electric power to automatically clean clothes. The user adds laundry detergent, which is sold in liquid, powder, or dehydrated sheet form, to the wash water. The machines are also found in commercial laundromats where customers pay-per-use. History Washing by hand Laundering by hand involves soaking, beating, scrubbing, and rinsing dirty textiles. Before indoor plumbing, it was necessary to carry all the water used for washing, boiling, and rinsing the laundry from a pump, Water well, well, or Spring (hydrology), spring. Water for the laundry would be hand-carried, heated on a fire for washing, and then poured i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fabric Softener
A fabric softener (American English) or fabric conditioner (British English) is a conditioner applied to laundry after it has been washed in a washing machine. A similar, more dilute preparation meant to be applied to dry fabric is known as a wrinkle releaser. Fabric softeners reduce the harsh feel of items dried in open air, add fragrance to laundry, and/or impart anti-static properties to textiles. In contrast to laundry detergents, fabric softeners are considered a type of after-treatment laundry aid. Fabric softeners are available either in the form of a liquid, typically added during the washing machine's rinse cycle, or as dryer sheets that are added to a tumble dryer before drying begins. Liquid fabric softeners may be added manually during the rinse cycle, automatically if the machine has a dispenser designed for this purpose, through the use of a dispensing ball, or poured onto a piece of laundry to be dried (such as a washcloth) which is then placed into the dryer. Wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
